By Paulette Lutz

When I was a child traveling on Route 1 in Elkridge with my parents, I remember passing the world’s largest dog house on a gentle rise on the west side of Route 1 just south of Route 175.

Many long-time residents in the county remember it as the One Spot Flea Killer building. The three-story building constructed in the shape of a Chow glowed at night from a 65 foot neon sign on the north and south sides of the building espousing “Home of One Spot Flea Killer.”

In 1933, Willis E. Simpson, college graduate, a U. S. Army veteran of World War I, lawyer, inventor, self-trained architect and unabashed huckster constructed the landmark from recycled wood (from a demolished five-room school house) and covered it in white stucco.

He started in this location as a large dog-boarding facility called Kennel Gardens. He also bred Chows and other dogs at his kennel.

It was here that he met a chemical engineer by the name of Mr. Allen who mentioned that a compound called Rotenone killed ticks on dogs.

Simpson began to experiment with a plant-based chemical which he named Ken-Gar-Dust. He gave away free samples to advertise his breeding and boarding kennels.

Simpson decided that he could make more money by selling the flea powder than running a dog hotel. Thus, One Spot Flea Killer was born – so named because one spot of the powder anywhere on the dog killed not only fleas, but lice, ants, aphids, bedbugs, crab lice, potato bugs, cabbage worms and Mexican bean beetles.

Simpson claimed his product was safe for warm-blooded animals, “A cat can lick this powder off of his coat without being poisoned,” he stated.

However, it was determined years later that Rotenone had been fatal to humans when ingested in large quantities. Today it is used to kill invasive fish.

Here is an advertisement from The Evening Sun dated July 7, 1947:




With travelers driving the only road between Baltimore and Washington, D.C. (it was the I-95 of its day) thousands of people were fascinated with this huge curiosity of a building.

While his business was growing rapidly, Simpson added a 150 X 30 foot swimming pool for his employees and neighbors instead of them swimming in the river.

He also built dozens of coops to raise domestic and game fowl such as chickens, turkeys, ducks, geese, peafowl, pheasants and quail. Mr. Simpson subdivided his property with the intention of building houses.

In 1940, Simpson published a 176-page book called Symposiums, full of his homespun wisdom with his theories on everything from dog breeding to swimming pool construction.

In a chapter called “Publicity Stunts,” he believed his success was due to the fact that his building was on a heavily traveled main artery on the east coast estimating that 20,000 vehicles passed his “dog house” every day.

This area grew and it became known to the locals as “One Spot Town.”

One Spot Town was not without some notoriety. According to locals, it was a relay station for moonshiners. In the Jan. 15, 1947 Ellicott City Times, the following article appeared:

State’s Attorney Pulls Raid on Washington Blvd., One Spot Owner Held

State’s Attorney Daniel M. Murray and a group of law enforcement officers raided the One Spot [i.e. Tavern], located on Washington Blvd., last Saturday afternoon and confiscated alcoholic beverages being sold on the premises without the proper license.

The night previous, according to reports, a fight had taken place at the One Spot. The principals were given a hearing Saturday morning.  The raid took place early Saturday afternoon.

Irene Smith, Negro, said to be the owner, is being held by the State’s Attorney’s office for further action by the Howard Grand Jury.

In researching this case, the records indicated that Irene G. Smith applied for a Class D Beer license for her One Spot Tavern on July 9, 1947. The application was denied because the Maryland State Police stated that they had been called to the establishment five times for fights and one time for robbery.

The novelty dog house fascinated travelers for years.

The business was closed and the largest dog house in the world was demolished in 1974. However, the building lives on as one of the most notable memories of Howard Countians. The area now houses motels and business parks.

Mr. Willis E. Simpson died at 88 in 1976 after a short illness.

Paulette Lutz is a historian and researcher for the Howard County Historical Society, a registered DAR genealogist and has lived in Howard County for over 60 years.